Nanoscale Assembly. Chemical techniques. Edited by Wilhelm T. S. Huck

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Books
Nanoscale Assembly
Chemical techniques. Edited by
Wilhelm T. S. Huck.
Springer Verlag,
Heidelberg 2005.
244 pp., hardcover
E 76.95.—ISBN
0-387-23608-2
The timely topic of Nanoscale Assembly
encompasses such a large and expanding
body of work that W. T. S. Huck was
both wise and insightful to focus the
scope of his book onto Chemical techniques. Moreover, by gathering authors
with contrasting backgrounds in chemistry and physical chemistry, the editor
showed a genuine will to stimulate a
debate about a still emerging discipline.
Consequently, the enthusiastic reader
will be exposed successively to microstructured polymers (Chapters 1 and 2),
molecular electronics in self-assembled
monolayers (Chapters 3 and 5), supramolecular assembly on solid surfaces or
in solution (Chapters 4, 7, and 6), and
templated crystallization of colloidal
suspensions (Chapter 8). However,
expectations are quickly disappointed
by the vague and conventional viewpoint of the preface, the lack of a
structured outline, and the ill-defined
aims that have influenced the choice of
contributions. This inevitably translates
into loosely connected, sometimes
redundant, chapters, which address the
title theme with very variable success.
Chapter 1 is a rigorous account by U.
Steiner of simple concepts for tailoring
the topography and structure of poly-
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mers by demixing blends or controlling
capillary instabilities. The chosen examples are convincing, and the electric
field, temperature gradient, and van der
Waals dewetting techniques are
reported precisely. The section about
modeling is very clearly written, and the
chapter ends with perspectives towards
complex multilayered patterns. In striking contrast, Chapter 2 by W. T. S. Huck
also describes pattern formation in polymers, but in a very confused style. The
section on polymer blend demixing is
completely redundant, and of poorer
quality than the treatment in Chapter 1.
The remainder of the chapter on block
copolymer demixing and dewetting
lacks a general structure, and is generally wordy and sometimes too speculative. The chapter nevertheless benefits
from a more informative section on
polymer brushes. A common shortcoming of these two chapters is their focus
on large micrometer-scale structuring,
with no envisioned extension to truly
nanometer-scale assembly. Chapter 3,
by M. A. Reed, and Chapter 5, by J. M.
Tour, both deal with molecular electronics in self-assembled monolayers,
and should have been placed one after
the other. That would also have exposed
the
numerous—and
foreseeable—
redundant sections (and even redundant
figures!) and led to better editing. These
two chapters offer state-of-the-art
reviews on electrical (Chapter 3) and
chemical
(Chapter 5)
techniques
required for generating molecular
monolayers and characterizing their
transport properties. One would wish
that the authors had not merely listed
the existing approaches, but rather
assessed or critically reviewed them for
a better understanding of the present
standing of molecular electronics in an
era of maturity after some early
euphoric years. For reasons that are
not clear, D. N. Reinhoudt8s excellent
Chapter 4 on hydrogen-bonded rosette
self-assembly and pavement of solid
interfaces has been intercalated
between Chapters 3 and 5. This chapter,
along with Chapter 7, is certainly the
one most accurately related to the
book8s title. Simple molecules obtained
by modifying calixarenes with hydrogen-bonding moieties are shown to selfassemble into genuine nanoscale assemblies upon addition of a hydrogen-bond
* 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
acceptor. Synthetic chemistry strategies
are well described, thermodynamic and
spectroscopic data on colloidal aggregates are given, and scanning probe
microscopy images of highly ordered
2D assemblies are interpreted. This text
demonstrates very elegantly how chemical systems can be tailored towards
versatile nanometer-scale objects. A
natural link could have been established
with Chapter 7 from R. J. M. Nolte8s
group, which is a very comprehensive
review on the use of amphiphiles for
building nanoscale assemblies and
objects. The description starts at a very
basic level with simple lipids and biological surfactants, and then moves to
synthetic phospholipids, amino acid and
peptide amphiphiles, glucoamides, etc.
For each system, the relationship
between molecular structure and assembly morphology is described, with
numerous illustrations of assembled
nanoobjects. After that, an entire section is dedicated to block copolymer
amphiphiles and another one to biohybrid surfactants that result from the
coupling of biomolecular moieties (proteins, enzymes, etc.) to synthetic blocks.
Both types of surfactants are reviewed
with the same thoroughness. The whole
50-page chapter is carefully matched to
the book8s scope, and it is extremely
pleasant to read, in spite of the too
numerous errors in the legends and
labeling of figures.
An extension of Chapter 7 towards
bioarray applications is developed in
Chapter 6 by P S. Cremer. Supported
phospholipid bilayers are shown to be
convenient synthetic equivalents of cell
membranes. The authors describe the
incorporation of ligand biomolecules
(e.g., antigens, proteins) within the
bilayers and their micropatterning into
bioarrays. Faster measurements of binding efficiency are achieved by integrating microfluidics concepts. The chapter
is pleasant to read and well organized,
but here again one wonders why a topic
describing—and needing—micrometerscale features was selected to illustrate
“nanoscale assembly”. Also, the references are rather old and, for example, a
perspective on the current challenges in
detection methods for real nano-bioarrays for improved screening protocols
would have been appreciated.
Angew. Chem. Int. Ed. 2006, 45, 4544 – 4545
Angewandte
Chemie
With Chapter 8 the book definitely
leaves the realm of nanoscale molecular
self-assembly to give a glimpse of microscale colloidal self-organization. After
briefly reviewing aspects of colloid synthesis, Y. Xia shows how microspheres
can be ordered into well-defined aggregates, based on geometrical considerations. That is followed by a rather
conventional section on high-quality
colloidal crystals, with a more ingenious
closing paragraph on microlens arrays.
Although it is outside the book8s main
framework, the chapter thoroughly
explores a couple of simple concepts,
and it is nicely illustrated by the chosen
experimental results.
Surely, youre joking Mr. Whitesides!
… but if R. Feynman8s bestseller triggers both smiles and scientific meditation, Chapter 9 does neither and leaves
the reader bewildered. Indeed, anyone
interested in nanoscale assembly will
certainly be familiar with G. M. Whitesides8s remarkable work, and will rightfully consider it to be a sizeable collection of truly innovative and inspiring
ideas. Yet, Chapter 9 consists of an
Angew. Chem. Int. Ed. 2006, 45, 4544 – 4545
excruciating accumulation of trivial or
obscure statements (e.g., “The history of
predicting revolutions is poor, and it is
likely that any revolution will emerge
from an unexpected direction.”—
p. 221), a few wrong assertions, such as
the paragraph on molecular electronic
phenomena, which are globally described as “so unclear that it will be
impossible to interpret” (p. 228)—an
opinion that Reed and Tour have certainly appreciated—but not an ounce of
up-to-date science. Upon reaching
page 230 and reading “The first step
toward the capability to design and
synthesize nanostructures for selfassembly is simply to expand the range
of syntheses and methods of fabrication
that lead to nanostructures”, the reader
wonders how Whitesides could write
such a repetitive collection of nonsense.
One would prefer that he, or his coauthors, did not. My advice: skip the
chapter!
To summarize from an epistemological viewpoint, this book is symptomatic
of the difficulties the scientific community is currently experiencing in defining
what nanoscience really is. Notwithstanding this existential questioning,
and in spite of disparities between
chapters, many of the individual contributions are good introductions to their
respective fields. Furthermore, they are
not intellectually challenging, and the
few in-depth parts are adequately
detailed. Therefore, this book could be
useful for students or for general multidisciplinary reading, but it is definitely
not suitable for experts in any of the
fields mentioned. As I indicated earlier,
it would have gained immensely from
more rigorous attention by the editor
and typesetters. So we shall still keep
“plenty of room at the bottom” of our
shelves for a future masterpiece on
“Nanoscale Assembly”.
Erik Dujardin
Nanosciences Group
CEMES, CNRS
Toulouse (France)
DOI: 10.1002/anie.200585378
* 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.angewandte.org
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